1. Field of the Invention
The present invention is broadly concerned with a leak identification and containment device adapted for application to a valve assembly which protrudes from a wall surface, such as a transformer tank valve. The identification and containment device includes a flexible bag formed of light-transmitting material having an internal absorbent lining and size to envelop the valve assembly. If a leak occurs, the lining becomes discolored, thereby giving an immediate visual indication of the leak.
2. Description of the Prior Art
Electrical substations normally have a series of large transformers, which are typically mounted above grade on pedestal structure. Such transformers include an oil tank as a part thereof, with the tank having a protruding drain valve. Transformer oil often contains polychlorinated biphenyls (PCBs) which are deemed to be environmentally hazardous. Over the course of time, transformer tank valves can develop leaks. Consequently, the transformer oil may spill on the ground adjacent the transformer site, causing ground pollution. While substation employees may periodically inspect the transformer tank valves for leaks, there may be substantial periods between the inspections. Therefore, considerable pollution can occur even though proper monitoring procedures are followed.
U.S. Pat. Nos. 4,556,082, 6,244,290 and 6,164,345 describe jackets designed for application to in-line valves and pipe fittings. Of necessity, such jackets must be specially designed for particular kinds of valves and line sizes. Moreover, they are generally formed as a unitary piece which is wrapped about an in-line valve and secured thereto. This creates seams in the valve enclosure which are subject to leaking. Further, these devices do not envelop and enclose the entire valve assembly, i.e., the operating handle of the valve extends outwardly from the jacket. Thus, any leaks which occur at the handle area of the valve are not contained. Finally, these jackets are not specifically designed to give a rapid visual indication of valve leakage by absorbing material escaping from a valve.
U.S. Pat. No. 5,878,776 illustrates an insulating jacket for protecting an exterior faucet against freeze-up in cold weather conditions, and is made up of a plurality of concentrically arranged plastic bags with insulating fill between adjacent bags. A similar insulating unit is shown in U.S. Pat. No. 2,985,552. U.S. Pat. No. 5,725,009 discloses a device for containing and redirecting fluid released when a fitting is removed from the end of a pipe. These devices are not designed for long-term application to a valve assembly and provide no leak indicating function.
Finally, U.S. Pat. Nos. 1,965,227, 2,250,980 and 4,603,432 disclose miscellaneous absorbent and indicator packages, and collapsible spill containment assemblies. None of these patents deal with the specific problem of exterior valve leakage.
The present invention overcomes the problems outlined above and provides an improved leak identification and containment device adapted for application to a valve assembly protruding from a wall surface, there valve assembly including a conduit and a selectively operable valve having an operating handle and material outlet. A particular application for the devices of the invention is in the context of transformer tank valves, although the invention is not limited to this field of use. The identification and containment device includes a flexible bag formed of light-transmitting synthetic resin material which is at least translucent (and preferably substantially transparent) having a valve-receiving opening configured to receive the valve including the handle and outlet thereof, as well as a portion of the valve stem or conduit. A cinch strap is provided adjacent the open end of the bag and is operable to close the bag opening around the valve conduit to thereby fully enclose the valve including the handle and outlet. The bag includes an absorbent lining along at least a portion of the interior thereof adjacent the valve outlet. The lining has a color which will change in the event of leakage of material from the valve to allow visual determination of whether the valve is leaking.
The valve bag may be formed from a variety of flexible synthetic resin materials such as polyurethane, polyethylene, polyvinyl or polypropylene. The absorbent lining can likewise be fabricated from a large number of absorbent materials, although blown polypropylene is preferred. If desired, the bag may include additional features such as a drain fitting and/or a secondary access opening. The bag may be of virtually any shape so long as it may accommodate the entire valve assembly to be protected.
In use, the bag is opened and slid over the valve assembly including the handle and outlet, and the cinch strap is used to draw the bag opening around the valve conduit. In this manner, the entirety of the valve is within the confines of the bag. In the case of a transformer valve leak identification and containment device, it is preferred that the absorbent lining be white or light grey in color. Thus, if transformer oil begins to leak the lining is immediately darkened which can be easily observed. At the same time, the leakproof heat-sealed bag seams (which avoid folded-over sections which could allow leakage) contains the leaking transformer oil to prevent pollution.